为什么分离签名的验证会导致 OpenPGP.js 的 "Message digest did not match" 错误？

Question

我可以毫无问题地通过 gpg 对测试文件进行签名和验证，但是通过 OpenGPG.js 验证签名失败并出现错误“消息摘要不匹配”。这是为什么？

$ gpg --armor --quiet --batch --yes --detach-sig index.html
$ gpg --verify index.html.asc index.html
gpg: Signature made Wed 25 Nov 2020 08:26:34 PM PST
gpg:                using RSA key C361FDC3F93B9E8F8BD7E08D5F873051B2D6C347
gpg: Good signature from <key>
$ node sandbox.js 
{ signatures:
   [ { keyid: [Keyid],
       verified: [Promise],
       signature: [Signature],
       valid: false,
       error:
        Error: Message digest did not match
            at Signature.verify (/home/caleb/src/islands/node_modules/openpgp/dist/openpgp.js:41176:11)
            at process._tickCallback (internal/process/next_tick.js:68:7)
            at Function.Module.runMain (internal/modules/cjs/loader.js:834:11)
            at startup (internal/bootstrap/node.js:283:19)
            at bootstrapNodeJSCore (internal/bootstrap/node.js:623:3) } ],
  data: 'Test!\n' }

sandbox.js（基于the OpenPGP.js example）：

openpgp = require('openpgp');
fs = require('fs');

async function sandbox() {
    path = './'

    let msg_data = fs.readFileSync(path + "index.html", 'utf8');
    let sig_data = fs.readFileSync(path + "index.html.asc", 'utf8');
    let pubkey_data = fs.readFileSync(path + "pubkey.asc", 'utf8');

    let msg = await openpgp.cleartext.fromText(msg_data);
    let sig = await openpgp.signature.readArmored(sig_data);
    let pubkey = await openpgp.key.readArmored(pubkey_data);

    openpgp.verify({
        message: msg,
        signature: sig,
        publicKeys: pubkey.keys
    }).then(function(verified) {
        console.log(verified);
    });
}

sandbox();

index.html:

Test!

index.html.sig:

pubkey.asc:

npm list 显示 openpgp@4.10.8.

Answer 1

Ingo Klöcker 回答了这个问题on the gnupg users mailing list。总而言之，gpg 的默认操作模式使用非签名时的文本模式，它显示 OpenPGP.js 默认为文本模式（至少在这里使用的方式）。将 --textmode 添加到 gpg 命令行允许 OpenPGP.js 验证签名，从而解决了问题。

如果不需要文本模式，也可以从文件中读取二进制数据：

...
    let msg_data = fs.readFileSync(path + "index.html", null);
    let sig_data = fs.readFileSync(path + "index.html.sig", null);
    let pubkey_data = fs.readFileSync(path + "pubkey.asc", 'utf8');

    let msg = await openpgp.message.fromBinary(msg_data);
    let sig = await openpgp.signature.read(sig_data);
    let pubkey = await openpgp.key.readArmored(pubkey_data);

    openpgp.verify({
        message: msg,
        signature: sig,
        publicKeys: pubkey.keys
    }).then(function(verified) {
        console.log(verified);
    });
...

为什么分离签名的验证会导致 OpenPGP.js 的 "Message digest did not match" 错误？

Why does verification of a detached signature result in a "Message digest did not match" error for OpenPGP.js?

javascript

openpgp

openpgp.js